School-slate



A. KAOHLER.

$011001; SLATE.

(No Model.)

No. 245,726. Patented Aug. 16,1881.

V UNITED STATES PATENT OFFICE.

ALBERT KACHLER, OF NEW HAVEN, CONNECTICUT.

SCHOOL-SLATE.

SPECIFICATION forming provement in School-Slates; and I do hereby declare the following, when taken in connection with the accompanying drawings, and the letters of reference marked thereon, to be a full, clear, and exact description-0t the same, and which said drawings constitute part of this specification, and represent, in-- Figure 1, the slate with the square applied in broken lines; Fig. 2, perspective view of the square.

This invention relates to an improvement in slates for schools and like purposes, with special reference to that class of slates which are provided with a frame.

In many school-exercises it is necessary that the slate should be ruled with parallel lines and equally spaced. To this end it is a common practice to make the lines with a metal point, so as to cut or scratch the surface, and so that the lines may be permanent, for the reason that with ordinary appliances itis very difficult for the pupil to make the lines parallel and equally spaced. The scratching or V permanent ruling injures that side of the slate part of Letters Patent No. 245,726, dated August 16, 1881.

Application filed May 12, 1881.

(No model.)

In the illustration I show a common schoolslate, A, with the usual four-sided frame, B. On one edge-say the left hand, in the position shown-I make a series of notches, 1 2 3 4, &c., and on the opposite side like notches at a difl'erent distance from each other, and at the ends similar notches.

The instrument used as the guide for making the lines is a common T-square, as seen in Fig. 2, in which C is the blade and D the T.

At thejunction of the blade and T a point or stud, a, projects, preferably at the center of the tongue and on the working-edge of the T. The square is placed upon the slate, as seen in Fig. 1, the stud a entering one of the notches, and so that the T will come hard against the edge of the slate, holding the square in that position until the line is made, then withdrawing the square until the stud a escapes from its notch. The square is moved to the next notch, or to the notch where the next line is to be made, and so on; or if narrower ruling is required, turn .to the opposite edge; or if combined ruling-as, for instance, as seen in broken lines at the notch 2 3 and intermediate lines-one series of lines maybe made from one side and the other series from the opposite side; or if vertical lines are required, work in like manner from either or both ends of the frame.

1 claim- A slate having its frame or edge constructed with a series of notches, combined with a T- square provided with a stud or projection to engage the said notches, substantially as described.

ALBERT KACHLER. Witnesses JOHN E. EARLE, LILLIAN D. RoeERs. 

